Food and Drug Administration guidances on biosimilars: an update for the gastroenterologist

The management of inflammatory bowel disease (IBD), a significant cause of morbidity in the United States (US), has been revolutionized over the last two decades by the introduction of biologic therapies. These include antitumor necrosis factor α (TNF-α) agents. Since 2016, five biosimilar TNF-α inhibitors have been approved by the US Food and Drug Administration (FDA) for use in the treatment of IBD. The FDA has published a series of guidance documents related to the evaluation, licensing, and approval of biosimilars. The aim of this review is to provide an overview of these FDA guidances and the issues associated with biosimilars in the US.